Social Security and Medicare Data to the NRC/NAS Twin Registry

Data on identical and fraternal twins have proven to be an invaluable resource for research on aging because of the ability to utilize the “twin design” in order to (a) control for unobserved endowments – including genetic dispositions and family backgrounds – in behavioral analyses of health outcomes, and (b) conduct behavioral genetic analyses that disentangle genetic, shared environment and non-shared environmental factors. Because of the lack of a large-scale national twin registry covering important agingrelated aspects in old age twins in the United States, most of this research has used twin registries from other countries, including Denmark, Sweden, and Australia. To the extent that U.S. specific institutional settings, such as implied by the U.S. social security system, the health care system, the labor market and many aspects of the U.S. socioeconomic environment, are important determinants of health outcomes, research using non-U.S. based twin data is limited in its ability to inform important questions related to the health determinants and the implications of aging in the United States.